Early vs Delayed Surgery in Dogs with Intervertebral Disk Extrusion

In the literature

Martin S, Liebel FX, Fadda A, Lazzerini K, Harcourt-Brown T. Same-day surgery may reduce the risk of losing pain perception in dogs with thoracolumbar disc extrusion. J Small Anim Pract. 2020;61(7):442-448.

The Research …

Surgical timing for suspected intervertebral disk extrusion (IVDE) cases is controversial in veterinary medicine. Clinicians often attempt to maximize outcomes by promoting expedient referral for emergency surgery when necessary. This decision-making process becomes more complicated in after-hours situations. In paraparetic and paraplegic dogs, presence of deep pain is a clear prognostic indicator for improved outcomes after surgery, with 88% to 96% of dogs regaining ambulation; once deep pain is gone, the patient’s ability to regain voluntary ambulation lowers significantly (50%-60%).^1-3 When surgery is indicated for an after-hours patient, the clinician must determine whether surgery is needed overnight or can wait until the next day. Spinal surgery requires precise therapy by the surgical team, and precise therapy may not be maximal in the middle of the night. In human medicine, it has been well-documented that after-hours surgery is a risk factor for development of complications.^4,5

This study retrospectively examined the effect of surgical decompression timing for IVDE on dogs’ ability to regain ambulation. Dogs with paraparesis or paraplegia with deep pain were included in the study. Dogs were admitted and had surgery either the same day or after an overnight delay; 273 dogs qualified for the study. Dogs with earlier surgery (ie, between days 0 and 1) had decreased hospitalization times and better odds for recovery to voluntary ambulation. Seven of 151 (5%) dogs in the early surgery group lost deep pain postoperatively; 15 of 122 (12%) dogs in the delayed surgery group lost deep pain. Five of 7 (71.4%) dogs in the early surgery group that lost deep pain perception regained ambulation within 3 weeks; 8 of 15 (57.1%) dogs in the delayed surgery group that lost deep pain perception regained ambulation. This suggests that an overnight delay may decrease the odds of regaining ambulation.

The biggest weakness of this study is its retrospective nature. Case selection for which cases were to have same day surgery versus delayed surgery provides an unknown bias. In addition, return to voluntary ambulation was based on a pet owner survey, not evaluation by a clinician. Prospective studies would be beneficial to investigate the effects of early versus delayed surgery in IVDE cases.

… The Takeaways

Key pearls to put into practice:

• Presence of pain perception remains the best prognostic indicator for eventual voluntary ambulation in dogs with IVDE.

• Performing surgery in nonambulatory dogs prior to loss of deep pain perception is ideal; however, this can create a difficult situation after hours with regard to balancing expedient care with a potentially compromised surgical team. This study data suggest that only a small percentage of surgically delayed cases experience detrimental long-term outcomes.

• Paraplegic cases should be prioritized for surgical decompression so surgery may occur before loss of deep pain. It is important to note that even with expedient surgery not all dogs maintain or regain deep pain sensation.

• A small percentage of dogs deteriorate neurologically despite surgical decompression, suggesting timing of surgery in these dogs may be less clinically imperative.

• Early referral can help promote improved outcomes due to optimal planning and timing. Ideally, surgery should occur during the day, when the surgical team is fully supported and may demonstrate the greatest procedural acumen, and on a patient that has not lost deep pain sensation.